DESCRIPTION (Applicant's abstract): There is a current need to monitor food and fish tissue samples for total mercury and other toxic metals, onsite, using portable instruments. Currently the determination of mercury requires complex instrumentation, which is beyond the means of potential users. Moreover, the samples have to be shipped to an accredited lab with typical turnaround times of 10 days or more. The fish tissue sample preparation involves a tedious procedure of hot, concentrated, acid digestion. This Phase I research will examine the feasibility of using screen-printed electrodes with dendrimer-gold nano composite for the "in situ" anodic stripping voltammetric analysis (ASV) of total mercury in fish tissue samples. Alternate methods of sample preparations will be tested. The dendrimeric structure due to its hydrophilicity and density of the molecular arms are expected to prevent the influx of large organic and biomolecules. With the advent of nano scale molecular reservoirs such as the dendrimers, and excellent opportunity exists to test the idea of rapid chemical sensing in a biomimetric manner. The screen-printed electrodes will be fabricated at the New Mexico State University Microfabrication Labs using our proprietary formulations. A thorough characterization of the proposed electrode, using certified fish tissue samples for "proof of the concept" will be carried out. The product from this research would be well suited for portable automated commercial instruments such as the MetalyzerTM, SA-5000 or Tracelab TM systems using the current EPA protocols for mercury analysis by stripping methods. The cost of the proposed electrode strips is comparable to the current cost of electrodes. The ASV has remarkably low detection limits and can analyze a variety of toxic metals due to the unique stripping potentials for each metal. PROPOSED COMMERCIAL APPLICATION: The proposed electrodes strips have a massive potential for use in field tests for agriculture and food industry. Water quality as well as for routine monitoring of industrial waste water treatment facilities to monitor low levels of toxic mercury and other medals. Multianalyte sensing capabilities could be incorporated. The US and European market for the proposed sensors is projected to be close to 400 million dollars by the year 2005.